JP2022116799A - Adhesive sheet for electronic component transfer and method for processing electronic component using adhesive sheet for electronic component transfer - Google Patents

Abstract

To provide an adhesive sheet for electronic component transfer, wherein the adhesive sheet is excellent in terms of both the fixability and detachability of an electronic component, prevents defects such as breakage even when the electronic component is small and thin, thus enabling the reception and delivery of the electronic component.SOLUTION: This adhesive sheet for electronic component transfer comprises a substrate and an adhesive layer disposed on at least one side of the substrate, wherein the adhesive layer has a nano indenter elastic modulus of 500 MPa or less at 25°C, following irradiation with ultraviolet rays of 460 mJ/cm2.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to an electronic component transfer pressure-sensitive adhesive sheet and a method for processing an electronic component using the electronic component transfer pressure-sensitive adhesive sheet.

Conventionally, when an electronic component arranged on a predetermined member is transferred to another member, the electronic component is received with an adhesive sheet, and then the electronic component is transferred to another member. there is For example, when incorporating an LED chip into a device, the LED chip formed on the member is once transferred onto an adhesive sheet and received, and then the LED chip is transferred from the adhesive sheet to a predetermined device or member. Then, the LED chips are transferred.

As described above, a pressure-sensitive adhesive sheet having an active energy ray-curable pressure-sensitive adhesive layer can be used as the pressure-sensitive adhesive sheet for temporarily fixing the electronic component (that is, for receiving and then transferring the electronic component). Such a pressure-sensitive adhesive sheet exhibits a predetermined adhesive force before irradiation with an active energy ray (e.g., ultraviolet rays) and can preferably fix an electronic component, and after irradiation with an active energy ray, the adhesive layer hardens to reduce adhesive strength, making it easier to pick up electronic components.

2. Description of the Related Art In recent years, there has been a trend toward frequent use of electronic components that have been made smaller and thinner. Small and thin electronic parts do not have sufficient contact area with the adhesive sheet, and are easily damaged when peeled off. A pressure-sensitive adhesive sheet having an agent layer is preferably used. However, especially in a small and thin electronic component (for example, 100 μm square or less, thickness 30 μm or less), when the electronic component is received and fixed, the electronic component is embedded in the adhesive layer at a high rate, and then the adhesive Even after curing the agent layer, the problem arises that it is difficult to peel off and is easily damaged.

JP-A-2020-53558

The present invention has been made to solve the above-mentioned conventional problems, and its object is to improve both the fixing property and the peeling property of electronic components, so that even if the electronic components are small and thin, To provide a pressure-sensitive adhesive sheet for electronic component transfer that enables receipt and delivery of the electronic component while preventing problems such as breakage.

The electronic component transfer pressure-sensitive adhesive sheet of the present invention comprises a base material and a pressure ^- sensitive adhesive layer disposed on at least one side of the base material. The nanoindenter elastic modulus at °C becomes 500 MPa or less.
In one embodiment, the pressure-sensitive adhesive sheet has a sinking amount of 3 μm to 27 μm in a 40° C. environment using TMA.
In one embodiment, the pressure-sensitive adhesive layer has a thickness of 2.1 μm to 35 μm.
In one embodiment, the pressure-sensitive adhesive layer has a normal state nanoindenter elastic modulus at 25° C. of 0.4 MPa or more.
In one embodiment, the pressure-sensitive adhesive layer has a normal probe tack value of 8 N/cm ² or more.
In one embodiment, the substrate is made of a polyester-based resin.
In one embodiment, the substrate has a thickness of 30 μm to 200 μm.
In one embodiment, the electronic components are mini-LEDs or micro-LEDs.
In one embodiment, the electronic component transfer pressure-sensitive adhesive sheet includes the pressure-sensitive adhesive layer, the base material, and another pressure-sensitive adhesive layer in this order.
According to another aspect of the present invention, a method of processing an electronic component is provided. This processing method is a method of processing an electronic component using the electronic component transfer adhesive sheet, comprising a step a of transferring the electronic component placed on the first member onto the adhesive layer of the adhesive sheet; and a step b of picking up the electronic component by a second member and peeling the electronic component from the adhesive sheet.
In one embodiment, the electronic components are mini-LEDs or micro-LEDs.
In one embodiment, the step b includes a step b-1 of contacting the second member with the electronic component on the adhesive layer, and a step b- of irradiating the adhesive sheet with an active energy ray. 2 and a step b-3 of picking up the electronic component by the second member and peeling the electronic component from the adhesive sheet.
In one embodiment, the first member is a sapphire substrate.
In one embodiment, the electronic component is a micro LED, and in the step a, the sapphire substrate on which a plurality of micro LEDs are arranged is irradiated with UV laser light to attach the micro LED to the adhesive sheet. Including transcribing.
In one embodiment, a portion of the micro LED arranged on the sapphire substrate is selectively transferred to the adhesive sheet.

According to the present invention, an electronic component that is excellent in both fixability and peelability of the electronic component, prevents problems even when the electronic component is small and thin, and enables receiving and delivery of the electronic component. A transfer adhesive sheet can be provided.

1 is a schematic cross-sectional view of an adhesive sheet according to one embodiment of the present invention; FIG. 4 is a schematic cross-sectional view of a pressure-sensitive adhesive sheet according to another embodiment of the invention; FIG.

A. Outline of Electronic Component Transfer Adhesive Sheet FIG. 1 is a schematic sectional view of an electronic component transfer adhesive sheet according to one embodiment of the present invention. An electronic component transfer pressure-sensitive adhesive sheet 100 according to this embodiment includes a base material 10 and a pressure-sensitive adhesive layer 20 disposed on at least one side of the base material 10 . FIG. 2 is a schematic cross-sectional view of an adhesive sheet according to another embodiment of the invention. The adhesive sheet 200 according to this embodiment comprises an adhesive layer 20, a substrate 10, and another adhesive layer 30. FIG.

The adhesive layer 20 contains an active energy ray-curable adhesive. A pressure-sensitive adhesive layer containing an active energy ray-curable pressure-sensitive adhesive is cured and its adhesive force is lowered by irradiating it with an active energy ray. The electronic component transfer pressure-sensitive adhesive sheet (hereinafter also simply referred to as the pressure-sensitive adhesive sheet) of the present invention has a predetermined adhesive strength before being irradiated with active energy rays, and can preferably fix electronic components. On the other hand, after irradiation with active energy rays, the adhesive strength is lowered as described above, and the electronic component can be easily peeled off (handed over).

The adhesive layer 20 has a nanoindenter elastic modulus of 500 MPa or less at 25° C. after being irradiated with ultraviolet rays of 460 mJ/cm ² . The nanoindenter elastic modulus is obtained by continuously measuring the load applied to the indenter and the depth of indentation when the indenter is pushed into the sample (for example, the adhesive surface) during loading and unloading. It refers to the elastic modulus obtained from the applied load-indentation depth curve. The details of the method for measuring the nanoindenter elastic modulus will be described later. The above ultraviolet irradiation is performed, for example, by using an ultraviolet irradiation device (manufactured by Nitto Seiki Co., Ltd., trade name “UM-810”) and applying ultraviolet rays from a high-pressure mercury lamp (characteristic wavelength: 365 nm, integrated light amount: 460 mJ/cm ² , irradiation energy: 70 W. /cm ² , irradiation time: 6.6 seconds).

In general, when an electronic component is fixed on an adhesive layer, part (or all) of the electronic component can be buried in the adhesive layer, thereby exerting a predetermined fixing force. On the other hand, when the electronic parts are peeled off, the embedding of the electronic parts becomes a factor that hinders the peelability. In the present invention, the nanoindenter elastic modulus of the adhesive layer after curing is within the above range, so that the electronic component on the adhesive layer has a high degree of freedom of movement in the plane direction, and a part of the electronic component is It is possible to provide a pressure-sensitive adhesive sheet that allows the electronic component to be easily peeled off even if it is buried. By using such a pressure-sensitive adhesive sheet of the present invention, even when small and thin electronic components (for example, mini LEDs and micro LEDs) are attached, it is possible to re-peel them without damaging the electronic components. Become. In addition, as described above, since favorable releasability is exhibited, sufficient embedding of electronic components is allowed, and as a result, the pressure-sensitive adhesive sheet of the present invention is also excellent in fixability of electronic components.

The initial adhesive force at 23° C. when the adhesive layer of the adhesive sheet is attached to a stainless steel plate (SUS304) is preferably 0.1 N/20 mm to 30 N/20 mm, more preferably 0.1 N/20 mm to It is 15N/20mm. With such a range, it is possible to obtain a pressure-sensitive adhesive sheet that can hold electronic components well. Adhesion is measured according to JIS Z 0237:2000. Specifically, the pressure-sensitive adhesive sheet was attached to a stainless steel plate (arithmetic mean surface roughness Ra: 50 ± 25 nm) by reciprocating a 2 kg roller once, left at 23 ° C. for 30 minutes, peeled at a peel angle of 180 °, and pulled. It is measured by peeling off the adhesive sheet at a speed of 300 mm/min. The pressure-sensitive adhesive layer changes its adhesive strength by irradiation with active energy rays, and in this specification, the "initial adhesive strength" means the adhesive strength before irradiation with active energy rays.

In one embodiment, the adhesive layer of the adhesive sheet is attached to a stainless plate (SUS304), and the adhesive force at 23° C. after irradiation with ultraviolet rays of 460 mJ/cm ² is preferably from 0.01 N/20 mm. It is 0.3 N/20 mm, more preferably 0.02 N/20 mm or more and less than 0.2 N/20 mm. Within such a range, a pressure-sensitive adhesive sheet with excellent peelability can be obtained. The adhesive strength after ultraviolet irradiation can be measured after the adhesive layer is adhered to an adherend and then the adhesive surface is irradiated with ultraviolet rays.

The thickness of the adhesive sheet is preferably 1 μm to 300 μm, more preferably 3 μm to 200 μm.

The pressure-sensitive adhesive sheet preferably has a sinking amount of 2 μm to 35 μm, more preferably 3 μm to 27 μm, still more preferably 4 μm to 25 μm, and particularly preferably 5 μm to 5 μm in an environment of 40° C. using TMA. 20 μm. Within this range, it is possible to obtain a pressure-sensitive adhesive sheet in which the electronic component, which is the adherend, is appropriately embedded in the pressure-sensitive adhesive layer, and which is excellent in fixability (i.e., receiving properties) and peelability (i.e., delivery properties). can. “The amount of sinking in a 40° C. environment using TMA” means the amount of sinking after 20 minutes have passed since the probe was brought into contact with the adhesive layer using a thermomechanical analyzer (TMA). The measurement conditions are probe diameter: 1.0 mm, mode: penetration mode, nitrogen gas flow rate: 50.0 ml/min, pushing load: 0.5 N, measurement ambient temperature: 40°C.

B. Adhesive Layer As described above, the nanoindenter elastic modulus of the adhesive layer at 25° C. becomes 500 MPa or less after irradiation with ultraviolet rays. The pressure-sensitive adhesive layer has a nanoindenter elastic modulus at 25° C. after irradiation with ultraviolet rays of 460 mJ/cm ² , more preferably 450 MPa or less, more preferably 400 MPa or less, and 350 MPa or less. is particularly preferred, and 300 MPa or less is most preferred. With such a range, the above effect becomes remarkable. In addition, the pressure-sensitive adhesive layer has a nanoindenter elastic modulus at 25° C. after irradiation with ultraviolet rays of 460 mJ/cm ² , preferably 1 MPa or more, more preferably 5 MPa or more, and 10 MPa or more. is more preferable, 50 MPa or more is particularly preferable, and 100 MPa or more is most preferable. Within such a range, it is possible to obtain a pressure-sensitive adhesive sheet which is excellent in fixability and which enables delivery of electronic components with high positional accuracy. The elastic modulus of the pressure-sensitive adhesive layer can be determined by any appropriate method, such as the composition of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, the structure of the polymer contained in the pressure-sensitive adhesive, the type and amount of the cross-linking agent contained in the pressure-sensitive adhesive, etc. can be adjusted by

The normal state nanoindenter elastic modulus of the pressure-sensitive adhesive layer at 25° C. is preferably 0.1 MPa to 55 MPa, more preferably 0.2 MPa to 40 MPa, still more preferably 0.3 MPa to 30 MPa, and particularly preferably. is 0.3 MPa to 20 MPa. Within such a range, it is possible to obtain a pressure-sensitive adhesive sheet that is excellent in fixing electronic components. "Normal state nanoindenter elastic modulus" means the elastic modulus before irradiation with active energy rays.

In one embodiment, the normal state nanoindenter elastic modulus of the pressure-sensitive adhesive layer at 25° C. is preferably 10 MPa or less, more preferably 8 MPa or less, and still more preferably 3 MPa or less. Within such a range, it is possible to obtain a pressure-sensitive adhesive sheet that is particularly excellent in fixing properties of electronic components.

In another embodiment, the normal state nanoindenter elastic modulus of the pressure-sensitive adhesive layer at 25° C. is preferably 0.4 MPa or more, more preferably 0.5 MPa or more, and still more preferably 0.8 MPa or more. be. Within such a range, transferability is improved when electronic components are transferred from a predetermined member (for example, a sapphire substrate) to an adhesive sheet and the electronic components are received by the adhesive sheet. In this way, a pressure-sensitive adhesive sheet having excellent transferability when receiving an electronic component can be obtained by a process (for example, a PSLLO process) in which only a part of a plurality of electronic components arranged on a predetermined member is selectively received by the pressure-sensitive adhesive sheet. It is particularly useful in

The normal storage modulus of the pressure-sensitive adhesive layer at 25° C. is preferably 10 MPa or less, more preferably 5 MPa or less, still more preferably 0.01 MPa to 3 MPa. "Normal storage modulus" means the modulus before irradiation with active energy rays. A method for measuring the storage modulus will be described later.

The pressure-sensitive adhesive layer preferably has a tensile elastic modulus of 0.05 MPa to 100 MPa, more preferably 0.1 MPa to 70 MPa at 25° C. after irradiation with ultraviolet rays of 460 mJ/cm ² . A method for measuring the tensile modulus will be described later.

The thickness of the pressure-sensitive adhesive layer is preferably 1.5 μm to 50 μm, more preferably 2.1 μm to 35 μm, still more preferably 3 μm to 30 μm. Within this range, it is possible to obtain a pressure-sensitive adhesive sheet in which the electronic component, which is the adherend, is appropriately embedded in the pressure-sensitive adhesive layer, and which is excellent in fixability (i.e., receiving properties) and peelability (i.e., delivery properties). can.

In one embodiment, the thickness of the adhesive layer is preferably 40 µm or less, more preferably 30 µm or less, and even more preferably 20 µm or less. By reducing the thickness of the adhesive layer, transferability is improved when electronic components are transferred from a predetermined member (for example, a sapphire substrate) to the adhesive sheet and the electronic components are received by the adhesive sheet. In this way, a pressure-sensitive adhesive sheet having excellent transferability when receiving an electronic component can be obtained by a process (for example, a PSLLO process) in which only a part of a plurality of electronic components arranged on a predetermined member is selectively received by the pressure-sensitive adhesive sheet. It is particularly useful in

The normal probe tack value of the pressure-sensitive adhesive layer is preferably 8 N/cm ² or more, more preferably 12 N/cm ² or more, still more preferably 15 N/cm ² or more. Within such a range, it is possible to obtain a pressure-sensitive adhesive sheet having excellent fixing properties for electronic components. The upper limit of the normal probe tack value of the pressure-sensitive adhesive layer is, for example, 60 N/cm ² . A method for measuring the probe tack value will be described later. "Normal state probe tack value" means a probe tack value before irradiation with an active energy ray.

The pressure-sensitive adhesive layer preferably has a probe tack value of 15 N/cm ² or less, more preferably 12 N/cm ² or less after being irradiated with ultraviolet rays of 460 mJ/cm ² . Within such a range, a pressure-sensitive adhesive sheet with excellent peelability can be obtained.

(Active energy ray-curable adhesive)
As described above, the adhesive layer contains an active energy ray-curable adhesive.

Examples of the base polymer constituting the pressure-sensitive adhesive include acrylic polymers, rubber polymers (e.g., natural rubber, chloroprene rubber, styrene-butadiene rubber, nitrile rubber, etc.), polyesters, urethane polymers, polyethers, and silicone polymers. Polymers, polyamides, fluorine-based polymers, ethylene-vinyl acetate-based polymers, epoxy-based resins, vinyl chloride-based polymers, cyanoacrylate-based polymers, cellulose-based polymers (nitrocellulose-based polymers, etc.), phenolic resins, polyimides, polyolefins, styrene-based polymers , polyvinyl acetate, polyvinyl alcohol, polyvinyl acetal, polyvinylpyrrolidone, polyvinyl butyral, polyvinylbenzimidazole, melamine resin, urea resin, resorcinol-based polymer, and the like. These polymers may be used individually by 1 type, and may be used in combination of 2 or more type. Acrylic polymers and rubber polymers are preferable, and acrylic polymers are more preferable, from the viewpoints of adhesion, cost, and the like. In addition, a "base polymer" means the main component of the polymer contained in an adhesive. The polymer is preferably a rubber-like polymer that exhibits rubber elasticity in a temperature range around room temperature. In this specification, the term "main component" refers to a component contained in an amount exceeding 50% by weight unless otherwise specified.

As the acrylic polymer, for example, a polymer of monomer raw materials containing an alkyl (meth)acrylate as a main monomer and a copolymerizable sub-monomer with the main monomer is preferable. Here, the main monomer refers to a component that accounts for more than 50% by weight of the monomer composition in the monomer raw material. The content of the main monomer is preferably 60 to 100 parts by weight, more preferably 70 to 99.5 parts by weight, per 100 parts by weight of the total amount of monomers in the starting monomer material.

As the alkyl (meth)acrylate, for example, a compound represented by the following formula (1) can be preferably used.
_CH2 =C( ^R1 ) ^COOR2 (1)
Here, R ¹ in the above formula (1) is a hydrogen atom or a methyl group. R ² is a branched or linear alkyl group having 1 to 20 carbon atoms (hereinafter, such a carbon atom number range may be referred to as "C1-20"). R ² is preferably a branched or linear C1-14 alkyl group, more preferably a branched or linear C6-14 alkyl group, more preferably a branched or linear C8 -12 alkyl group.

Specific examples of the alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, Pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate and the like. These alkyl (meth)acrylates may be used singly or in combination of two or more. Among them, 2-ethylhexyl acrylate (2EHA) and lauryl (meth)acrylate (LA, LMA) are preferred.

In one embodiment, alkyl (meth)acrylates are used in which R ² is a branched or linear alkyl group having 8 or more carbon atoms. By using such a monomer as the main monomer, it is possible to obtain a pressure-sensitive adhesive sheet that has a preferable elastic modulus before and after curing and is particularly excellent in fixing properties and releasing properties of electronic parts. Examples of alkyl (meth)acrylates in which R ² is a branched or linear alkyl group having 8 or more carbon atoms include 2EHA, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (Meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl (meth)acrylate and the like. The content of structural units derived from alkyl (meth)acrylates in which R ² is a branched or linear alkyl group having 8 or more carbon atoms is preferably 60 parts by weight to 100 parts by weight with respect to 100 parts by weight of the base polymer. parts, more preferably 70 to 95 parts by weight.

A sub-monomer that is copolymerizable with the alkyl (meth)acrylate that is the main monomer can be useful for introducing cross-linking points into the acrylic polymer and increasing the cohesive strength of the acrylic polymer. Further, it is preferable to employ a monomer having a functional group (functional group a) capable of reacting with the functional group (functional group b) of the carbon-carbon double bond-containing monomer described below as a submonomer. As the submonomer, for example, the following functional group-containing monomer components can be used singly or in combination of two or more.
Carboxy group-containing monomers: ethylenically unsaturated monocarboxylic acids such as acrylic acid (AA), methacrylic acid (MAA), crotonic acid; ethylenically unsaturated dicarboxylic acids such as maleic acid, itaconic acid, citraconic acid and their anhydrides (maleic anhydride, itaconic anhydride, etc.);
hydroxyl group-containing monomers: hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate; Unsaturated alcohols such as vinyl alcohol and allyl alcohol; Ether compounds such as 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether and diethylene glycol monovinyl ether;
amino group-containing monomers: for example aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate;
epoxy group-containing monomers: for example glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, allyl glycidyl ether;
cyano group-containing monomers: e.g. acrylonitrile, methacrylonitrile;
Keto group-containing monomers: for example diacetone (meth)acrylamide, diacetone (meth)acrylate, vinyl methyl ketone, vinyl ethyl ketone, allyl acetoacetate, vinyl acetoacetate;
Monomers having a nitrogen atom-containing ring: such as N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinyl pyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholine, N-vinylcaprolactam, N-(meth)acryloylmorpholine;
Alkoxysilyl group-containing monomers: such as 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxy propylmethyldiethoxysilane;
Isocyanate group-containing monomers: (meth)acryloyl isocyanate, 2-(meth)acryloyloxyethyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate.
In addition, it is preferable not to use an amide group-containing monomer capable of forming a polymer having a high affinity with a metal from the viewpoint of maintaining releasability.

In one embodiment, a hydroxyl group-containing monomer is preferably used as the secondary monomer, and 2-hydroxyethyl (meth)acrylate can be more preferably used. By using the monomer, it is possible to obtain a pressure-sensitive adhesive sheet that has a preferable elastic modulus before and after curing, and is particularly excellent in the fixability and peelability of electronic parts.

The content of the structural unit derived from the submonomer is preferably 0.1 to 40 parts by weight, more preferably 1 to 30 parts by weight, per 100 parts by weight of the base polymer. Within such a range, it is possible to form a pressure-sensitive adhesive layer with high cohesion and excellent adhesiveness.

Further, as the base polymer, when using a base polymer having a carbon-carbon double bond as described later, as a secondary monomer, a functional group (functional group b) of the compound B having a carbon-carbon double bond described later It is preferable to use a submonomer having a functional group (functional group a) capable of reacting with. In such a case, the type of submonomer is determined by the compound B species described above. As the sub-monomer having the functional group a, for example, carboxy group-containing monomers, epoxy group-containing monomers, hydroxyl group-containing monomers and isocyanate group-containing monomers are preferable, and hydroxyl group-containing monomers are particularly preferable. By using a hydroxyl group-containing monomer as a sub-monomer, the acrylic polymer has a hydroxyl group. On the other hand, by using an isocyanate group-containing monomer as the compound B having a carbon-carbon double bond, the hydroxyl group of the acrylic polymer reacts with the isocyanate group of the compound, and the carbon derived from the compound B - Carbon double bonds are introduced into the acrylic polymer.

Further, for the purpose of increasing the cohesive strength of the acrylic polymer, etc., copolymerization components other than the sub-monomers described above can be used. Examples of such copolymerization components include vinyl ester monomers such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene, substituted styrene (α-methylstyrene, etc.) and vinyltoluene; (meth)acrylates, cycloalkyl (meth)acrylates such as isobornyl (meth)acrylate; aryl (meth)acrylates (e.g. phenyl (meth)acrylate), aryloxyalkyl (meth)acrylates (e.g. phenoxyethyl (meth)acrylate) , arylalkyl (meth)acrylates (e.g., benzyl (meth)acrylate) and other aromatic ring-containing (meth)acrylates; ethylene, propylene, isoprene, butadiene, isobutylene, and other olefin monomers; vinyl chloride, vinylidene chloride, and other chlorine Containing monomers; alkoxy group-containing monomers such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate; vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether; Copolymerization components other than these submonomers can be used singly or in combination of two or more. The amount of such other copolymerization component is, for example, 2 to 20 parts by weight with respect to 100 parts by weight of the total amount of monomers in the starting monomer material.

Furthermore, a polyfunctional monomer can be used as a copolymerizable component for the purpose of cross-linking the acrylic polymer. As the polyfunctional monomers, hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylol One or more of propane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy acrylate, polyester acrylate, urethane acrylate and the like can be used. The amount of the polyfunctional monomer is, for example, 30 parts by weight or less with respect to 100 parts by weight of the total amount of monomers in the monomer raw material.

The above acrylic polymer can be obtained by any appropriate polymerization method. For example, a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a suspension polymerization method, and the like can be mentioned.

Preferably, a carbon-carbon double bond is introduced into the base polymer (preferably acrylic polymer). By using a base polymer having a carbon-carbon double bond, it is possible to form a pressure-sensitive adhesive layer that is cured by active energy rays (typically ultraviolet rays). In the present invention, in addition to the above method, it is also possible to form a curable adhesive layer using an adhesive containing a polymerizable monomer or oligomer and an acrylic polymer. From the viewpoint of obtaining a pressure-sensitive adhesive sheet with excellent adhesion, it is preferable to form a curable pressure-sensitive adhesive layer using a base polymer having a carbon-carbon double bond.

Any suitable method can be employed to produce a base polymer having carbon-carbon double bonds. For example, there is a method of reacting a polymer A having a functional group a with a compound B having a functional group (functional group b) capable of reacting with the functional group a and a carbon-carbon double bond. In this case, it is preferable to carry out the reaction so that the carbon-carbon double bond does not disappear, and for example, a condensation reaction, an addition reaction, or the like can be employed. As the polymer A, for example, as described above, a polymer obtained by copolymerizing an alkyl (meth)acrylate as a main monomer and a sub-monomer having a functional group a is used.

Examples of the combination of the functional group a and the functional group b include a combination of a carboxy group and an epoxy group, a combination of a carboxy group and an aziridyl group, a combination of a hydroxyl group and an isocyanate group, and the like. Among them, a combination of a hydroxyl group and an isocyanate group is preferable from the viewpoint of reaction tracking. From the viewpoint of polymer design and the like, a combination in which the acrylic polymer has a hydroxyl group and the above compound has an isocyanate group is particularly preferable.

Examples of compounds having a carbon-carbon double bond and a functional group b include isocyanate group-containing monomers (isocyanate group-containing compounds). Among them, 2-(meth)acryloyloxyethyl isocyanate is more preferable.

The amount of the isocyanate group-containing monomer compounded is preferably 1 part by weight to 40 parts by weight, more preferably 100 parts by weight of the polymer before the carbon-carbon double bond is introduced (that is, the polymer A). It is 5 to 30 parts by weight, more preferably 8 to 15 parts by weight.

In addition, a carbon-carbon double bond may be introduced so that the hydroxyl groups possessed by the polymer A remain. By doing so, the degree of cross-linking can be increased when the pressure-sensitive adhesive layer is heated. In this case, the molar ratio (a/b) between the hydroxyl group as the functional group a and the isocyanate group as the functional group b is suitably greater than 1, preferably 1.1 or more.

The weight average molecular weight Mw of the base polymer (preferably acrylic polymer) is preferably 10×10 ⁴ to 500×10 ⁴ , more preferably 20×10 ⁴ to 200×10 ⁴ , and still more preferably 30×10 ⁴ to 100×10 ⁴ . Within such a range, it is possible to form a pressure-sensitive adhesive layer with little adhesive residue and excellent adhesion. In addition, in this specification, Mw means the value of standard polystyrene conversion obtained by GPC.

Preferably, the adhesive contains a cross-linking agent. Examples of cross-linking agents include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, oxazoline-based cross-linking agents, aziridine-based cross-linking agents, melamine-based cross-linking agents, peroxide-based cross-linking agents, urea-based cross-linking agents, metal alkoxide-based cross-linking agents, Examples include metal chelate cross-linking agents, metal salt cross-linking agents, carbodiimide cross-linking agents, amine cross-linking agents and the like. These cross-linking agents can be used singly or in combination of two or more.

The content of the cross-linking agent is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 8 parts by weight, with respect to 100 parts by weight of the base polymer of the adhesive. Within such a range, a pressure-sensitive adhesive layer having an appropriately adjusted nanoindenter elastic modulus can be formed.

In one embodiment, an isocyanate-based cross-linking agent is preferably used. An isocyanate-based cross-linking agent is preferable because it can react with various functional groups. Specific examples of the isocyanate-based cross-linking agents include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; aromatic isocyanates such as tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate; trimethylolpropane/tolylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name “Coronate L”), tri Methylolpropane/hexamethylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate HL"), hexamethylene diisocyanate isocyanurate (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate HX"), etc. isocyanate adduct; and the like. Preferably, a cross-linking agent having 3 or more isocyanate groups is used.

The isocyanate-based cross-linking agent is preferably added so that the number of functional groups of the isocyanate-based cross-linking agent is 10 mol% to 50 mol% with respect to the number of functional groups capable of reacting with the isocyanate-based cross-linking agent in the base polymer. , 20 mol % to 40 mol %. By adding such an amount, it is possible to form a pressure-sensitive adhesive layer in which the nanoindenter elastic modulus is appropriately adjusted.

The pressure-sensitive adhesive may further contain any appropriate additive as necessary. The additives include, for example, photopolymerization initiators, tackifiers, plasticizers (e.g., trimellitate ester plasticizers, pyromellitic ester plasticizers), pigments, dyes, fillers, antioxidants, Conductive agents, ultraviolet absorbers, light stabilizers, release modifiers, softeners, surfactants, flame retardants, antioxidants, solvents and the like.

C. Substrate The substrate may be composed of any suitable resin. Examples of the resin include polyolefin-based resins such as polyethylene-based resins, polypropylene-based resins, polybutene-based resins, and polymethylpentene-based resins, polyurethane-based resins, polyester-based resins, polyimide-based resins, polyetherketone-based resins, and polystyrene-based resins. Examples include resins, polyvinyl chloride resins, polyvinylidene chloride resins, fluorine resins, silicone resins, cellulose resins, ionomer resins, and the like.

In one embodiment, a base made of a polyester-based resin is used as the base. A base material composed of a polyester-based resin preferably has rigidity, and the use of the base material can prevent misalignment when fixing an electronic component.

The thickness of the substrate is preferably 2 μm to 300 μm, more preferably 5 μm to 200 μm, still more preferably 10 μm to 200 μm.

In one embodiment, a substrate having a thickness of 30 μm to 200 μm (preferably a substrate made of polyester resin) is used. By using a substrate having such a thickness, it is possible to prevent misalignment when fixing the electronic component.

D. Separate Adhesive Layer The separate adhesive layer can be composed of any appropriate adhesive. The adhesive may be a curable adhesive or a pressure-sensitive adhesive. The separate pressure-sensitive adhesive layer includes, for example, a pressure-sensitive adhesive such as an acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, or a silicone pressure-sensitive adhesive.

The thickness of the separate adhesive layer is, for example, 1 μm to 100 μm.

E. Production method of pressure-sensitive adhesive sheet The above-mentioned pressure-sensitive adhesive sheet can be produced by any appropriate method. A pressure-sensitive adhesive sheet can be obtained, for example, by applying the above pressure-sensitive adhesive onto a base material. Coating methods include bar coater coating, air knife coating, gravure coating, gravure reverse coating, reverse roll coating, lip coating, die coating, dip coating, offset printing, flexographic printing, screen printing, etc. Various methods can be employed. Alternatively, a method of forming a pressure-sensitive adhesive layer on a release liner and then attaching it to a base material may be adopted.

F. How to use the adhesive sheet (how to process electronic parts)
The pressure-sensitive adhesive sheet of the present invention can be used when transferring the electronic component between members in any appropriate electronic component processing step. For example, in one embodiment, a method of processing an electronic component using the pressure-sensitive adhesive sheet is provided, and the processing method comprises (a) removing the electronic component arranged on a first member from the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet; (b) picking up the electronic component with a second member and peeling off the electronic component from the adhesive sheet (receiving the electronic component from the adhesive sheet); pass) step b. Any suitable processing steps may be performed before step a, between steps a and b, and after step b.

In one embodiment, a plurality of the electronic components are arranged on the first member. In one embodiment, in the step a, all the electronic components arranged on the first member are transferred onto the adhesive sheet. In another embodiment, a portion of the electronic component placed on the first member is selectively transferred onto the adhesive sheet.

In one embodiment, the step b includes a step b-1 of bringing the second member into contact with the electronic component on the adhesive layer, and the adhesive sheet (substantially the adhesive layer). and a step b-3 of picking up the electronic component by the second member and peeling the electronic component from the adhesive sheet.

In one embodiment, the electronic component can be an LED. In one embodiment, the LEDs may be mini-LEDs or micro-LEDs. A mini-LED is, for example, an LED chip with a size of 100 μm or more on one side, and has a structure in which a growth support substrate such as a sapphire substrate is adjacent to a light-emitting (epitaxial) layer mainly composed of gallium nitride. In this specification, an LED chip having a growth supporting substrate such as a sapphire substrate is defined as a mini-LED even if one side is 100 μm or less. One side of the mini LED chip is, for example, 50 μm to 500 μm, and the thickness is, for example, 30 μm to 200 μm. Further, a micro LED is, for example, one side of an LED chip is 100 μm or less, a light emitting (epitaxial) layer containing gallium nitride as a main component is separated from a growth support substrate such as a sapphire substrate, and only the light emitting (epitaxial) layer has a structure In this specification, an LED chip that does not have a growth support substrate such as a sapphire substrate is defined as a micro LED even if one side is 100 μm or more. One side of the micro LED chip is, for example, 5 μm to 200 μm, and the thickness is, for example, 3 μm to 30 μm.

In one embodiment, the electronic component is an LED (preferably micro LED) and the first member is a sapphire substrate. In such an embodiment, in step a, the sapphire substrate on which the LEDs are arranged is irradiated with UV laser light to transfer the LEDs to the adhesive sheet. Here, the LED is separated from the sapphire substrate by irradiating UV laser light and chemically decomposing the interface between the sapphire substrate and the LED. Specifically, gallium nitride present near the interface between the sapphire substrate and the LED is decomposed into liquid metal gallium and gaseous nitrogen by UV laser light irradiation, and the LED is separated from the sapphire substrate. In one embodiment, all the LEDs arranged on the sapphire substrate are transferred onto the adhesive sheet. In another embodiment, a portion of the LED arranged on the sapphire substrate is selectively transferred onto the adhesive sheet.

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these Examples. Tests and evaluation methods in Examples are as follows. Also, "parts" and "%" are by weight unless otherwise specified.

(1) Nanoindenter elastic modulus Using a nanoindenter (manufactured by Hysitron Inc., trade name "Triboindenter TI-950"), a single indentation method at a predetermined temperature (25 ° C.) was performed at an indentation speed of about 500 nm / sec. The elastic modulus of the surface of the pressure-sensitive adhesive layer was measured under the measurement conditions of a drawing speed of about 500 nm/sec and an indentation depth of about 3000 nm under normal conditions and after irradiation with ultraviolet rays of 460 mJ/cm ² .

(2) Storage modulus of pressure-sensitive adhesive layer in normal state Using a dynamic viscoelasticity measuring device (manufactured by TA instruments, trade name “ARES-G2”), measurement frequency 1 Hz, strain 0.05%, storage at 25 ° C. Elastic modulus G' and loss factor tan δ were measured. Specifically, using the normal pressure-sensitive adhesives obtained in Examples and Comparative Examples, a pressure-sensitive adhesive sheet having a thickness of 50 μm without a substrate was prepared, and the pressure-sensitive adhesive sheet was made to have a thickness of 1.0 mm or more. , and punched into a size of φ8 mm using a jig, and set on a probe of ARES-G2. -50°C to 200°C at 5°C/min. was measured at a heating rate of From the obtained data, the value of storage modulus G' at 25°C was extracted.

(3) Tensile elastic modulus of the pressure-sensitive adhesive layer after irradiation with ultraviolet rays of 460 mJ/cm ² Using a dynamic viscoelasticity measuring device (manufactured by TA Instruments, trade name “RSA-3”), measurement frequency 1 Hz, strain A tensile modulus E' at 0.05% and 25°C was measured. Specifically, using the adhesives obtained in Examples and Comparative Examples, adhesive sheets having no substrate having a thickness of 50 μm were produced, and the adhesive sheets were laminated to a thickness of 200 μm or more. A sample with a width of 10 mm was obtained by removing the release liner after irradiating the sample with a release liner on both sides of the sample with ultraviolet rays of 460 mJ/cm ² once from each side. The distance between chucks was 20 mm, and the temperature was changed from 0°C to 200°C at 5°C/min. was measured at a heating rate of From the obtained data, the value of the tensile modulus E' at 25°C was extracted.

(4) Probe tack A double-sided adhesive tape (Nitto Denko Co., Ltd., product name “No. 5600”) is applied to the entire surface of the evaluation surface of the adhesive sheet (width 20 mm × length 50 mm) opposite to the adhesive layer. It was attached to a slide glass (26 mm×76 mm, manufactured by Matsunami Glass Industry Co., Ltd.) using a 2 kg hand roller. Next, the probe tack value of the exposed adhesive layer surface and the probe tack value after irradiating the exposed adhesive layer surface with 460 mJ / cm ² ultraviolet rays were measured with a probe tack measuring machine (manufactured by RHESCA, trade name " TACKINESS Model TAC-II"), probe descending speed (Immersion speed): 120 mm / min, test speed (test speed): 600 mm / min, adhesion load (Preload): Measurement was performed under the conditions of 20 gf and a contact holding time (press time) of 1 second. The measurement was performed with N=5, and the average value of these measured values was used as the probe tack value. In addition, the pressure-sensitive adhesive sheets of Examples 17 to 22 were attached to the slide glass with the pressure-sensitive adhesive surface opposite to the pressure-sensitive adhesive layer on the evaluation surface using a 2 kg hand roller, and probed under the same conditions as above. A tack value was measured.

(5) Adhesive strength The adhesive layer of the adhesive sheet is attached to SUS304BA, and the adhesive strength of the adhesive sheet is measured according to JIS Z 0237: 2000 (bonding conditions: one reciprocation of a 2 kg roller, tensile speed: 300 mm/min, peeling angle 180°, measurement temperature: 23°C). In addition, the adhesive layer of the adhesive sheet was attached to a polyethylene terephthalate film (manufactured by Toray Industries, Inc., trade name “Lumirror S10”, thickness: 25 μm), and the adhesive strength of the adhesive sheet to the polyethylene terephthalate film was measured according to JIS Z 0237: 2000 (bonding conditions: one reciprocation of a 2 kg roller, tensile speed: 300 mm/min, peeling angle of 180°, measurement temperature: 23° C.), and the adherend was peeled off from the pressure-sensitive adhesive sheet.
Further, after the adhesive layer was attached to the adherend as described above, the adhesive layer was irradiated with ultraviolet rays of 460 mJ/cm ² , and then the adhesive strength was measured by the method described above.

(6) TMA Subduction Depth Using a thermomechanical analyzer (manufactured by TA-instrument, trade name “TMA Q400”), using a φ1.0 mm probe, nitrogen gas flow rate: 50.0 mm in penetration mode. The sinking depth of the adhesive sheet was measured from the adhesive layer side under the conditions of 0 ml/min, indentation load: 0.5 N, measurement atmosphere temperature: 40°C, and indentation load time: 20 minutes. The measurement was performed with N=5, and the average value of N=3 excluding the maximum and minimum values among these measured values was taken as the sinking depth of the sample.

(7) Chip embeddability during lamination When the subduction depth of the adhesive sheet measured by thermomechanical analysis (TMA) is 3 μm or more and less than 27 μm, the embeddability is excellent (○ in the table), 27 μm or more. , the embeddability is excessive (x in the table).

(8) Amount of Deformation of Substrate The amount of deformation of the substrate was calculated by subtracting the adhesive layer thickness of the adhesive sheet from the sinking depth of the adhesive sheet measured by thermomechanical analysis (TMA). When the depth of sinking of the pressure-sensitive adhesive sheet was smaller than the thickness of the pressure-sensitive adhesive layer, it was assumed that there was no deformation of the substrate.

(9) Positional Accuracy of Chip When the amount of deformation of the substrate calculated from the subduction depth of the adhesive sheet measured by thermomechanical analysis (TMA) is less than 20 μm, the positional accuracy of receiving the chip is excellent ( ○ in the table), and if it is 20 μm or more, the positional accuracy in receiving the chip is insufficient (× in the table).

(10) Shear adhesive strength after irradiation with ultraviolet rays of 460 mJ/cm ² The pressure-sensitive adhesive sheets (size: 20 mm × 20 mm) obtained in Examples and Comparative Examples were placed on the opposite side of the pressure-sensitive adhesive layer to a predetermined base. (For example, 26 mm × 76 mm slide glass manufactured by Matsunami Glass Industry Co., Ltd.) and fixed, a 1 mm × 1 mm silicon chip is placed on the surface of the adhesive layer of the adhesive sheet, and the silicon chip is heated at 40 ° C. with a heat press. , and 0.05 MPa for 1 minute to prepare an evaluation sample. In addition, a double-sided adhesive tape (Nitto Denko Co., Ltd., trade name “No. 5600”) was used to fix the pressure-sensitive adhesive sheet without a separate pressure-sensitive adhesive layer to the base. Ultraviolet rays from a high-pressure mercury lamp (characteristic wavelength: 365 nm, integrated light intensity: 460 mJ/cm ² , irradiation energy: 70 W/cm ² , irradiation time: 6.6 seconds) was irradiated to the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet with the silicon chip to prepare an evaluation sample.
For the evaluation sample, using a Nordson dage4000 at an environmental temperature of 25 ° C., a measuring terminal was set on the side surface of a 1 mm × 1 mm silicon chip at a height of 50 µm from the attachment surface, and a shear rate of 500 µm / sec. The maximum breaking load was read from the load-displacement curve obtained by applying an external force in the horizontal direction to the chip at . The measurement was performed with N=5, and the average value of N=3, excluding the maximum and minimum values among these measured values, was taken as the shear adhesive strength of the sample.

(11) Transferability When the shear adhesive strength after irradiation with ultraviolet rays of 460 mJ/cm ² is less than 2000 N/cm ² , the transferability during chip transfer is excellent (○ in the table), 2000 N/cm When it is ² or more and less than 2,400 N/cm ² , the transferability when transferring the chip is good (Δ in the table), and when it is 2,400 N/cm ² or more, the transferability when transferring the chip is insufficient. (× in the table).

[Production Example 1] Preparation of acrylic polymer A 88.8 parts by weight of 2-ethylhexyl acrylate (2-EHA), 11.2 parts by weight of hydroxyethyl acrylate (HEA), and a polymerization initiator (manufactured by NOF CORPORATION, 0.2 parts by weight of the trade name "Nyper BW") and toluene were mixed. The obtained mixture was polymerized at 60° C. under a nitrogen gas stream to obtain an acrylic copolymer having a weight average molecular weight (Mw) of about 600,000.
To a toluene solution containing 100 parts by weight of an acrylic copolymer, 12 parts by weight of methacryloyloxyethyl isocyanate (MOI) and 0.06 parts by weight of butyltin dilaurate are added to cause an addition reaction of MOI to obtain a carbon-carbon An acrylic polymer A having double bonds was prepared.

[Production Example 2] Preparation of acrylic polymer B 91 parts by weight of lauryl methacrylate (LMA), 9.3 parts by weight of 2-ethylhexyl methacrylate (2-HEMA), and a polymerization initiator (manufactured by NOF Corporation, trade name 0.2 parts by weight of "Nyper BW") and toluene were mixed. The obtained mixture was polymerized at 60° C. under a nitrogen gas stream to obtain an acrylic copolymer.
To a toluene solution containing 100 parts by weight of an acrylic copolymer, 9.1 parts by weight of methacryloyloxyethyl isocyanate (MOI) and 0.04 parts by weight of butyltin dilaurate are added, and the MOI is subjected to an addition reaction to obtain carbon. - An acrylic polymer B with carbon double bonds was prepared.

[Production Example 3] Preparation of acrylic polymer C 100 parts by weight of 2-ethylhexyl acrylate (2-EHA), 25.5 parts by weight of acryloylmorpholine (ACMO), and 18.5 parts by weight of hydroxyethyl acrylate (HEA) , 0.2 parts by weight of a polymerization initiator (manufactured by NOF Co., Ltd., trade name "Niper BW") and toluene were mixed. The obtained mixture was polymerized at 60° C. under nitrogen gas stream to obtain an acrylic copolymer having a weight average molecular weight (Mw) of about 900,000.
8.5 parts by weight of methacryloyloxyethyl isocyanate (MOI) and 0.04 parts by weight of butyltin dilaurate are added to a toluene solution containing 100 parts by weight of an acrylic copolymer, and the MOI is subjected to an addition reaction to obtain carbon. - An acrylic polymer C with carbon double bonds was prepared.

[Production Example 4] Preparation of acrylic polymer D 75 parts by weight of 2-ethylhexyl acrylate (2-EHA), 15 parts by weight of acryloylmorpholine (ACMO), 22 parts by weight of hydroxyethyl acrylate (HEA), and a polymerization initiator (manufactured by NOF Co., Ltd., trade name "Niper BW") was mixed with 0.2 parts by weight of toluene. The obtained mixture was polymerized at 60° C. under a nitrogen gas stream to obtain an acrylic copolymer.
To a toluene solution containing 100 parts by weight of an acrylic copolymer, 17.7 parts by weight of methacryloyloxyethyl isocyanate (MOI) and 0.04 parts by weight of butyltin dilaurate are added, and the MOI is subjected to an addition reaction to obtain carbon. - An acrylic polymer D with carbon double bonds was prepared.

[Production Example 5] Preparation of acrylic polymer E 50 parts by weight of butyl acrylate (BA), 39 parts by weight of ethyl acrylate (EA), 20 parts by weight of hydroxyethyl acrylate (HEA), and a polymerization initiator (NOF Co., Ltd.) 0.3 parts by weight of Toluene was mixed with Toluene. The obtained mixture was polymerized at 60° C. under a nitrogen gas stream to obtain an acrylic copolymer.
To a toluene solution containing 100 parts by weight of an acrylic copolymer, 19.5 parts by weight of methacryloyloxyethyl isocyanate (MOI) and 0.06 parts by weight of butyltin dilaurate are added, and the MOI is subjected to an addition reaction to obtain carbon. - An acrylic polymer E with carbon double bonds was prepared.

[Production Example 6] Preparation of acrylic polymer F 30 parts by weight of 2-ethylhexyl acrylate (2-EHA), 70 parts by weight of methyl acrylate (MA), 10 parts by weight of acrylic acid (AA), After mixing 0.4 parts by weight of "Nyper BW" (trade name, manufactured by Yushi Co., Ltd.) and toluene, the mixture was heated at 70° C. to prepare a toluene solution of an acrylic copolymer (acrylic polymer F).

[Example 1]
To the toluene solution of the acrylic polymer A, 3 parts by weight of an isocyanate cross-linking agent (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate L") and a photopolymerization initiator ( BASF Corporation, trade name "Omnirad" (Omnirad 127): 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propane-1- On) 3 parts by weight were added to prepare an adhesive. The adhesive is coated on one side of a PET base material (100 μm, “Lumirror S1N” manufactured by Toray Industries, Inc.) to provide an ultraviolet curable adhesive layer (thickness: 2 μm). An adhesive sheet A (adhesive layer /PET substrate) was obtained.
The obtained adhesive sheet A was subjected to the above evaluation. Table 1 shows the results.

[Examples 2 to 16, Example 23, Comparative Examples 1 to 3]
Example 1 except that the acrylic polymer, cross-linking agent, tackifier, and photopolymerization initiator shown in Table 1 were used in the amounts shown in Tables 1 and 2, and the base material shown in Table 1 was used. A pressure-sensitive adhesive sheet was obtained in the same manner as above. The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Results are shown in Tables 1 and 2.
Compounds and the like used in Examples and Comparative Examples are as follows.
・ “YS Polyster S145”: terpene phenol-based tackifier, manufactured by Yasuhara Chemical Co., Ltd. ・ “UV-1700”: active energy ray-curable oligomer (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name “Shikou UV-1700B”)
・ “Omnirad 651”: manufactured by BASF, trade name “Omnirad 651”
・ “PET (printed product)”: PET film manufactured by Daisan Paper Co., Ltd. (thickness: 50 μm, light red solid printing)
・"PO": A propylene-based thermoplastic elastomer containing a propylene component and an ethylene-propylene rubber component (manufactured by Mitsubishi Chemical Corporation, trade name "Zelath") is supplied to a T-die molding machine (set temperature: 230°C) manufactured by Braco. and a substrate obtained by molding into a film with a thickness of 80 μm

[Example 17]
Adhesive sheet i (adhesive layer/ PET substrate) was obtained.
To a toluene solution containing 100 parts by weight of acrylic polymer G (a copolymer of 95 parts by weight of 2-ethylhexyl acrylate (2-EHA) and 5 parts by weight of acrylic acid (AA)), an epoxy-based cross-linking agent (Mitsubishi Gas Chemical A coating solution was prepared by adding 0.6 parts by weight of Tetrad C (trade name, manufactured by TETRAD Co., Ltd.). The coating liquid is applied to the surface of the adhesive sheet i opposite to the adhesive layer of the PET substrate, and the adhesive sheet I (adhesive layer/PET substrate/another adhesive layer (thickness: 30 μm)) was obtained. The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Table 3 shows the results.

[Examples 18 to 22]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 17, except that the base material having the thickness shown in Tables 3 and 4 was used. The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Results are shown in Tables 3 and 4.

REFERENCE SIGNS LIST 10 base material 20 adhesive layer 100, 200 adhesive sheet

Claims (15)

comprising a substrate and an adhesive layer disposed on at least one side of the substrate;
The pressure-sensitive adhesive layer has a nanoindenter elastic modulus of 500 MPa or less at 25° C. after being irradiated with ultraviolet rays of 460 mJ/cm ² .
Adhesive sheet for transferring electronic parts. 2. The pressure-sensitive adhesive sheet for transferring electronic components according to claim 1, wherein the pressure-sensitive adhesive sheet has a sinking amount of 3 μm to 27 μm in a 40° C. environment using TMA. 3. The pressure-sensitive adhesive sheet for electronic component transfer according to claim 1, wherein the pressure-sensitive adhesive layer has a thickness of 2.1 μm to 35 μm. The pressure-sensitive adhesive sheet for electronic component transfer according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive layer has a normal state nanoindenter elastic modulus at 25°C of 0.4 MPa or more. The pressure-sensitive adhesive sheet for electronic component transfer according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive layer has a normal probe tack value of 8 N/ ^cm2 or more. The pressure-sensitive adhesive sheet for electronic component transfer according to any one of claims 1 to 5, wherein the base material is composed of a polyester-based resin. The pressure-sensitive adhesive sheet for electronic component transfer according to any one of claims 1 to 6, wherein the substrate has a thickness of 30 µm to 200 µm. The pressure-sensitive adhesive sheet for transferring electronic parts according to any one of claims 1 to 7, wherein the electronic parts are mini-LEDs or micro-LEDs. The pressure-sensitive adhesive sheet for electronic component transfer according to any one of claims 1 to 8, comprising the pressure-sensitive adhesive layer, the base material, and another pressure-sensitive adhesive layer in this order. A method for processing an electronic component using the electronic component transfer pressure-sensitive adhesive sheet according to any one of claims 1 to 9,
a step a of transferring the electronic component arranged on the first member onto the adhesive layer of the adhesive sheet;
a step b of picking up the electronic component by a second member and peeling the electronic component from the adhesive sheet;
Processing method of electronic parts. 11. The method of processing an electronic component according to claim 10, wherein the electronic component is a mini LED or a micro LED. The step b is
a step b-1 of contacting the second member with the electronic component on the adhesive layer;
A step b-2 of irradiating the adhesive sheet with an active energy ray;
a step b-3 of picking up the electronic component by the second member and peeling the electronic component from the adhesive sheet;
The method for processing an electronic component according to claim 10 or 11. 13. The method of processing an electronic component according to claim 11, wherein said first member is a sapphire substrate. The electronic component is a micro LED,
14. The processing of an electronic component according to claim 13, wherein in the step a, the sapphire substrate on which a plurality of micro LEDs are arranged is irradiated with UV laser light to transfer the micro LEDs to the adhesive sheet. Method. 15. The method of processing an electronic component according to claim 14, wherein a portion of said micro LED arranged on said sapphire substrate is selectively transferred to said adhesive sheet.

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